Coolant filtration systems, such as associated with metal working machines, are well known in the art and which operate under the principle of successively filtering particles, shavings and other debris from a fluid coolant, such as further mainly consisting of some level of a treated water medium within which is dissolved a minor percentage of a natural or synthetic oil. Given the nature of the associated metal working machines, such as which can include conveyed removal of coolant immersed parts, it is found that significant percentages of the water content of the coolant (such as up to 50% within a 20-24 hour period) are evaporated.
Absent proper tracking and control, an overly oil rich coolant mixture (such as resulting from iterative addition of volumes of replenishment coolant exhibiting the initially fixed percentage of water to oil and which can exceed an arbitrarily desired range of 6-10% or higher oil emulsified within a water base) can result in significant greater expense and associated waste, and along with deleterious effect to coolant performance. Degradation of performance can further result from reverse emulsion of coolant into the water base (e.g. reduction or loss of immiscibility of the oil within the water with concurrent loss of effective surface area of contact within a machine cutting zone). It is further found that excessive oil to water percentage in the coolant further degrades associated coefficient of drag within the cutting zone.
Additional references are known which associate a central coolant reservoir with one or more machine located coolant filtration systems, these including such as the metalworking fluid central system of Johnson, U.S. Pat. No. 5,224,051, the central coolant system of Harms, U.S. Pat. No. 4,655,940, the coolant re-circulating arrangement and method of Bratten, U.S. Pat. No. 7,338,606 and the machine tool coolant filtration system of McEwan, U.S. Pat. No. 5,582,740.